3-D Shape Measurement Technique To Dynamic Process Objects

The application of 3-D shape measurement is more and more important in domain of modern industry, medical science, dress designing and video technology, etc. Since the optical three-dimension measurement is of high precision, non-touching and easy automation, it becomes very popular. With the development of technology, dynamic 3-D shape measurement has become one of the most important focuses in scientific research and application.Based on the static optical three-dimension measurement, a new method, dynamic 3-D reconstruction, of lip-moving by Fourier transform and color-encoding is brought forward. The theoretical analysis and experimental results are presented.Firstly, techniques for camera calibration are discussed. The application of perspective transformation matrix can reduce the error caused by the aberrance of camera.It is difficult to reconstruct the discontinuous lip by Fourier transform method. A modulation function has been brought forward in this paper. The modulation function can be calculated by Fourier transform, filtering and inverse Fourier transform. The value of modulation function in areas of local shadow and abrupt discontinuities is lower than that in other parts. So modulation is a useful threshold to determine the quality of carrier stripe. Phase unwrapping algorithm is used in the areas where the modulation higher than threshold.Finally, a novel system based on color-encoded structure light for 3-D shape measurement is presented in this paper. Each color stripe has a color and subsection to allow unique identification of a stripe given context of its neighbors. A pre-emphasise colors to avoid color distortions and thinner the slider at two directions are put forward. Because of the advantage of without phase unwrapping step, high precision and speedy account, color-encoded structure light used in dynamic 3-D shape measurement will be more popular.